JK23112

We all know and love the venerable Chevrolet 'small block' V8 engine that has been under the hood of many different GM cars and trucks - as well as being offered in various displacements from 265 to 400 cubic inches throughout the past five decades.

The best-known and most-beloved has to be the "350" or 5.7-liter version; especially with Chevrolet and GMC trucks. They are powerful, tough, reliable and it is relatively easy to "soup up" or increase their performance.

Now, at least with full-size Silverado & Sierra trucks, the times have changed and GM replaced the 5.7L with the newer 5.3L back in 2001 or so. I own a (purchased used) 2004 Silverado with the 5.3L and have about 84,000 miles on it. It runs strong, doesn't burn oil and has the low-end grunt for which the Chevy small block is famous.

The 5.7L and 5.3L are both OHV engines, two valves per cylinder and use timing chains rather than belts (Yes!). Aside from what appears to be a coil-on-plug (hence, the short wires), are there any other major differences? Are they still made with both two-bolt and four-bolt main blocks? Is it true they now are using aluminum cylinder heads rather than cast iron? Are they similar on the inside of the engine?

Does the 5.3L have the longevity of the venerable 5.7L? I have a friend with an '02 5.3L and he is approaching 150,000 miles with it - and with no engine trouble at all. Sounds like the old 350 to me!!

I take good care of my vehicles and use Mobil-1 synthetic oil; which I change every 3,000 to 3,500 miles whether it needs it or not. I also change the oil filter every time - and intend to do so as long as I have this truck.

Can I realistically expect 250k from my 2004 without an engine or tranny rebuild? I drive about 70 percent highway and 30 percent city and my engine has about 3,200 hours on it so far (again, I bought it used last February with 74,000 miles). I don't drive like an old man, but don't beat on it either.

I have had a "BG" fuel-injection service done, a DexCool radiator flush; as well as a "BG" transmission flush back at 76,000 miles. At 90k, it is going to get a power steering fluid flush done (again - last done at 40k) and the rear differential will be serviced. I am also considering new shock absorbers and a wheel alignment when I get the next set of tires installed. Once I hit 100k, I am going to have the sparkplugs replaced - as recommended by Mr. Goodwrench himself.


Anyone here have more than 150k on the 5.3L engine? Any problems? I have always been a "Ford" guy (hey, I admit it) and still love the Mustang and their Super Duty trucks - although they are WAY TOO EXPENSIVE; but I like my Chebby and plan on keeping it for a long time (since it will soon be paid off).

I appreciate any advice or input! Thank you so much!!


P.S. It is 2wd Silverado LS 1500, although it is shod with 4x4 rims (17-inchers) that a previous owner must have installed.

2003silveradoz71

I have 166,000 on my '03 Silverado Z71 all I have ever had to do is replace sensors. You see 250K on these motors all the time. I'm pretty disappointed with the mpg I get with my truck the best I get is about 12-13 mpg. What are you other guys getting?

Mille Racer 69

[Threadjack] It is putting around town and stop and go traffic that is killing your gas.
I just got back from a road trip and with the cruise control set at about 68 mph
I was only at 1,800 rpms. 1 way the trip was about 250 miles taking almost 3.5 hours
And I didn't even burn up a half a tank 1 way.
And FWIW I have a 5.7 L 1500.
This truck is not a good commuting vehicle, but reasonable for roadtrips.
I calculated that I was getting 18 MPG on average. [/threadjack]

smokenjoep01

The LS based 5.3 in trucks have iron heads. The cars have the all aluminum heads and blocks. Mine is a 1999 and has 170k and dosent even use oil between changes.
It does have a light knock first thing in the morning for a few minutes.

2003silveradoz71

Yes, I hear that is a common problem with high milage 5.3's My '03 has that as well. Is it easy to fix? Replace lifters?

smokenjoep01

Yes its a very easy fix. Turn up the radio!

Thumper_ehhhhh

The 5.3 also known as 327 has been around for more years as the 350. 1962 was there first year gm uses the 327 and the 350 wasnt introduced until 1967. So says wikipedia. Minus a few horsepower and torque they are a strong tried and tested work horse. I have 170000km on my 04 Burban and know many people with well over 200000 on there 5.3 and still going strong. Mine also burns no oil. Its the same level over the coarse of the oils life. 5000km. If you keep taking care of it there should be no reason it shouldnt keep going.

JK23112

So today's 5.3L is the same 327 that was in my grandfather's 1969 Impala? Are you sure about that?

I thought the newer 5.3L was a totally different block than the "old" 283, 305, 307, 327, 350, etc. -- and that the 4.8, 5.3 and 6.0L engines have a different type of cylinder head & coil-on-plug distributorless ignition.

Anyway, at least they are still overhead valve engines with timing chains rather than those stupid belts.


I have 84,000+ miles on my 2004 and plan to hang onto it for awhile.

Thumper_ehhhhh

Oh im sure the 5.3/327 is different now just like the 5.7/350 is different now. They are just engines that have been improved on. For one the hp now from a stock barebone 5.3 and 5.7 which is standard in all trucks there is no upgrade from the factory other than motor size. Which has much more hp than a stock barebone 327 and 350 of yesteryear. Back then you could get a stage one / stage 2 upgrade for motors or what ever each car make called them.What im saying is the 5.3 is not a new motor its been around a very long time and only improved over the years same as the 5.7. Now the 6 liter is not as old its like a 360ci. I trust something that has been around alot longer and just improved apon. With only 84000 miles on your truck if you treat it well you should have it for a very long time.

2003silveradoz71

I think the 5.3 is an entirely new motor. The cubic inches might be the same but with all new technology and design. Some good info on Chevy small block V-8's http://www.novak-adapt.com/knowledge...ion_III_v8.htm